Electric switch



Jan. 2, 1951 A. H. wlLsoN 2,536,522

ELECTRIC SWITCH Filed May 14, 1949 2 Sheets-Sheet 1 Illlll INVENTOR. HL/ AN H. W/Lso/ AGENT Jan. 2, 1951 A. H. wlLsoN ELECTRIC SWITCH Filed May 14, 1949 34 /O 6 52 53 72 I 3 Q :7'4" 5 20 35 34 3@ a 535? 72 2 Sheets-Sheet 2 HHN UH zl/ INVENTOR. ALLA/v WILSON .4 GEN T Patented Jan. 2, 1951 ELECTRIC SWITCH Allan H. Wilson, Arcadia., Calif., assignor to Zinsco Electrical Products Company, Los Angeles, Calif.

' Application May 14, 1949, Serial No. 93,327

1 "This invention relates generallv to circuit makers and breakers, and more particularly to electric switches of the enclosed, knife blade type.

f It is the practice in modern industrial switchboard installations, to provide a cabinet containing bus bars from the feeder lines and adapted to accommodate a number of switch units for controlling the supply of current from the switchboard to various locations on the property. These switch units, which are embodied in protecting boxes or casings of various sizes depending on the ampere rating of the switch, may be interchangeably mounted in the cabinet and plugged into the bus bars to electrically connect same to stationary contacts of the switch, all to the end oi greatly simplifying and facilitating the addition of switches to the board as well as the arrangement of switches thereon as the need arises. p

It is an obiect of this invention to provide an electric unit oi the above described character in whichbridging contacts for the stationary contacts of the switch are movably mounted in the cover of the switch box in such manner that with the cover closed, the stationary contacts may be bridged by the cover contacts to complete the electrical circuit therethrough, or remain unbridged, according as the cover contacts are moved to an active or inactive position when the cover is open, thus enabling the switch to be either open or closed with the cover closed, and to be locked in the preselected adiusted position so long as the cover is closed, whereby locking of the cover in closed position will eiiectively prevent anyone from tampering with the switch, and changing its position.

Anotheobject of this invention is to provide a switch unit as above set forth, in which a handle is movably mounted lon the cover oi the lswitch box and co-acts with a latching means to latch the c-over closed when the handle is disposed compactly on the front of the cover, or to unlatch the cover for opening and closing movements by the handle when disposed in a projecting position in which the handle may beconveniently grasped to manipulate the cover. Y f

A further object ofthe invention is to provide a switch unit which is structurally characterized to enable it to be competitively manufactured in quantity with the novel features of-this invention embodied in the unit.

With these and other objects in View, the in,`

vention resides in thev combinations, ,arrangee mentsand functional relationships of elements as 'setyforth inthe following specification and 7 claims. (ci. 20o- 50) particularly pointed out in the appended claims.

In the accompanying drawings,

Figure 1 is a view in front elevation, partly broken away, of one form of electric switchembodying this invention;

Figure 2 is a longitudinal sectional view taken on the line 2 2 of Figure '1;

Figure 3 is a transverse sectional View taken on the line 3-3 of Figure 1 and illustrating the closed position of the switch;

Figure 4 is a view similar to Figure 3 and vshowing the open position of the switch; and g Figure 5 is a fragmentary detail sectional view of a cover operating and latching handle-ern-v bodied in the switch.

Referring specifically to the drawings, myfinvention in its illustrated embodiment comprises a generally rectangular box or casing B composed of a body I0 and a anged cover I I mounted on the body at one end thereof by means of a hinge I2, to open or close the front of the body when the box is installed in a wall or floor cabinet (not shown)` ofthe well known plug-in type having a bus assembly into whose conductors the switch is plugged by means of conventional plug type contacts I5, I6 and Il, carried, respectively,Y by use'blocks I8, I9 and 20 of electrical insulating material and projecting from the insu# lated back wall 2l of the box, as best shown in Figures 2 and 3.

It will be noted from Figure 2, that three conductors or bus bars 22, 23 and 24 are shown dia-l grammatically in cross section, as the switch illustrated is particularly adapted for use in a three-wire system, although it will be clearly understood that the switch may be used in a4 two-wire system as well. The fuse blocks i 8, I9 and 20 are secured to flanges 25 and v26 in the body I0 at the back thereof by screws 2l having nuts 28, and are disposed side by side in proximity to each other as shown in Figures 1 and 3. The fuse blocks are provided with the usual load lugs 29 and pairs of clips A3B and 3i, for suitable cartridge fuses 32. Each load lug 29 is connected to `the respective cli-p 3l by -a conductor bar 32a, whereas each of the clips 30 -is connected by a conductorbar 33Y to the contact 34 oi a pair of stationary contacts 34 and 35 projecting from the respective fuse block into a socket 36 in a socket member 31- oi electrical insulating material spanning thev fuse blocks transversely at the end ofthe boxv remote from the hinge I2 and 4secured-to thev body' I0 by-certain ofthe screws'21. as shown in Figure' i1' i. j i-L' The stationary contacts 34 and 35 of each pair are spaced and insulated from each other by a separator 40 and are connected to the contacts I5, I6 and I'I of the line conductors 22, 23 and 24, respectively, to normally provide an open circuit at each pair of switch contacts 34, 35 between the respective line conductor and load clip 29. As this specific circuit arrangement is well known in the lart and Vforms no part, per se', of the present invention, further detailed description will be dispensed with.

Co-actable with each pair of contacts 3.1i, 35is. a bridging contact I, so that for the three-wire circuit illustrated, three bridging contacts are.: provided and are mounted VJor movement on the cover I I to occupy an active position wherein they bridge the respective pair of contacts. 3435 when the cover is closed, or an inactive position wherein they are clear of the contacts 34,. 35Jin the closed position of the cover. l A.-lor this purpose a support 55 .in the Vform of an elongated rectangular bar ot insulating material, issecuredbyscrews 52 `to the inside of the cover I I- lat a location which is directly -opposite the socket member 37 when the cover' is closed asA shown. The lsupport 5G is provided with a longitudinal guideway .53 .in Vwhich is reciprocably mounted an actuator 54 for the bridging contacts 5I.. which is provided with anger piece or knob 55 projecting through a slot,v 56 in the cover for manual actuation. to shift the actuator to one extreme position or the. other as shown inF-'igures 3,- andv. Aspring-pressed. ball `5l mcuntedin the actuator and urged .against the inner side of the cover II, co-acts with an instruck keeper lug 58 on the cover to releasably retain the actuator in either `entren-1e position.`

v Pivot pins 5t are .mounted .at .their ,ends in recesses -Bfl in thef actua-tor 54 and are confined in such. .recesses by the confronting tace of. the` Asupport 5c... Pivotally mounted` on the pins .aref

the .bridging contacts, v5 I. which are of generally U-shaped contour to provide spaced arms or blades 5d which are. urged kby llo-shaped spring. clips -64 to they contracted position shown in Egure` 4. and work. freely in slots 65. .in thesup.- port- 53. :Spanning the slots 65. transversely are cams 66 in the form A.of .iixed bars of insulating. material which are. stradded by the arms 63.0f the respective contacts 5I and co-act. therewith to positively swing the latter about the axes -of the. pins. Se to active-or inactive position accord ing as 'the Iactuator 54- is moved to one extreme position or.l the other when the cover is. open. Movement of the contacts to active position definitely limited by stop shoulders E? on vthe support 5G.

A handle 'L0 having a handegrip H, is pivotarly mounted by pins 'i2-on ears13- on the outsideof the. cover H at a. location remotev from the vhinge. l2, for swinging movement to occupy one position foruse as shown in Figures Lland 5, or anon-use position shown in Figures 1, 2 and V3. At one side, thel handle 'i0 is extended laterally to provide a latching hoo-k. 'Iy-4 working freely in. aslot '1 'l5- Lligurc `5)l .in the. cover il, for late hing en gageient with. a, keeper pin tin the -body I0,

so as to receive the hasp of a padlock (not shown) and lock the cover closed if desired to prevent any unauthorized access to the switch. The cover II is provided with a shallow depression opposite the hand-grip 1I, which enables the ngers of the operator to be readily applied to the hand-grip when the handle 'I0 is in non-use position, for swinging of the handle to its position for usey at which it is definitely limited by engagement of a stop shoulder 8I on the hook 'I4 vwith the wall of the cover at one end of the slot 'I5 as clearly shown in Figure 5.

The operation of the invention is as follows:

With the cover It open, the bridging contacts 5t may be moved to active or inactive position as desired; bymanipulation of the finger piece 55 to. shift the actuator 54 to one extreme position or the other, it being clear that this motion of the actuator eiects wiping engagement of one or the other of the arms 63 of the contacts 5I with the cams 63 to swing the contacts simultaneously and correspondingly about. the axes oi their respective .pivot `pins 6D. A

In. their active .position as; shown in. Figure, the lengths of the contacts 5I .are in :parallelism with the plane. of swinging movement of the cover, so that. upon. closing the latter withthe handle Til, the contacts 5l will enter the sockets` 35cm opposite sides of the separators 'in and. will be spread-slightly by the tapered'. noses oi the pairs ot contacts. 34, 35 against theurging action of thespri'ng. clips 54, and vthus make firm electrical and mechanical engagement therewith.` .The handle 'In is now swung to its non-use position so as to latch the cover closed, or tolock the. cover in closed position by the use of a suitable padlock.

To change the position of the contacts 5I.,l the cover I I is opened and the actuator 54 is shifted by thengerpiece 55 to. itsother extremeposition for co-action of the cams 66 with the arms 6.3 of the contacts 5l in moving the. latter to their inactive position shown in Figure 4,. in which their lengths extend at an obtuse angle with respect tothe plane of swinging. movement of the cover, with thecontacts being withdrawn almost entirely into the slots 65 of the support 5E).v Thus, upon closing. the cover, the contacts y5! will be incapable of bridging the pairs of contacts. 34, 35. so that the circuits will remain. broken.

From the foregoing description, it will be maui-- est that the circuits. may be made or broken at the pairs of stationary contacts. 34, 35 in. thebox by the bridging contacts 5I. when the cover Il is closed', depending upon. whether the contacts 5I have been moved when the: cover is open. to their active or .inactive position-, and that the cover may be securely latch-ed closed or lockedirrclosed position by the use of. a suitable. padlock..

rlfhe.mechanism of the switch may thus be entirely enclosed and adequately protected 'againstunauthorized access irrespective of whether the circuits are Vclosed or opened by the switch, vand that with the cover closed, the position of the contacts si 'cannotbe changed from thatV to which they have been adjusted when the cover iscpen, thus- .renderng the. switch tamperproot VI claim;- 1`. In: a switch of the class described, a box having a cover pivotally mounted thereon; a pair of insulated contacts supported in the box; 'a bridging contact; an actuatorreciprocably mountedon .said oever; :means pivotaliyA Viruzaunting said' bridging contactonxsaid actuator; anda'ixed; camonfthe cover with'wlhich said bridging con@ having a cover pivotally mounted thereon; a pair of contacts supported in the box and insulated from each other; a bridging contact having spaced contact arms; an actuator reciprocably mounted on said cover; a pivot pin carried by said actuator and on which said bridging contact is mounted; and a fixed cam on the cover, straddled by said arms of the bridging contact, for wiping co-action therewith in swinging the bridging contact upon said pivot pin to an active or inactive position according as said actuator is moved to one extreme position or another when the cover is open, for engagement of the bridging contact with said pair of contacts or disengagement therefrom accordingly, when the cover is open.

3. In a switch of the class described, a box having a cover pivotally mounted thereon; a pair of insulated contacts supported in the box; a U- shaped bridging contact providing spaced Contact arms and a connecting portion at one end thereof; a support secured to said cover and having a guideway; an actuator reciprocably mounted in said guideway and having a nnger piece accessi- `iol-e exteriorly of the cover; said actuator having alined recesses at opposite sides of said guideway; a pivot pin seated at its ends in said recesses and coniined therein by said support; said connecting portion of said bridging contact receiving said pin to pivotally mount the bridging contact thereon; a fixed cam on the support, straddled by said arms of the bridging contact, for wiping coaction therewith in swinging the bridging contact upon said pin to an active or inactive position according as said actuator is moved by said iinger piece to one extreme position or another when the cover is open, for engagement of the bridging contact with said pair of contacts or disengagement therefrom, accordingly, when the cover is closed; and means on the cover and actuator, co-acting to releasably retain the latter in either extreme position.

4. In a switch of the class described, the combination of a box; a cover hinged at one end to one end of said box in such a manner as to partially close the open side of said box when in its closed position; a pair of fixed contacts supported in and electrically insulated from said box and electrically insulated from each other; an actuator supported in said cover in such a Inanner as to be movable along a straight line within limits with relation to said cover, a bridging contact so shaped that in its bridging position it electrically connects one of said xed contacts with the other of said fixed contacts, said bridging contact being pivoted on said actuator; and a cam member fixed with relation tosaid cover and so placed as to swing said bridging contact about its pivot on said actuator as said actuator is moved from one of its limiting positions to the other. f

5. In a switch of the class described, the combination of: a box; a cover hinged at one end to one end of said box in such a manner as to partially close the open side of said box when in its closed position; a pair of xed contacts supported in and electrically insulated from said box and electrically insulated from each other; an actuator supported in said cover in such a manner as to be movable along a straight line within limits with relation to said cover; a U-shaped bridging contact so shaped that in its bridging position it electrically connects one of said fixed contacts with the other of said fixed contacts, said bridging contact being pivoted on said actuator; and

` a cam member xed with relation to said cover 70 Number and extending between the arms of said U-shaped bridging contact, being so placed as to swing said bridging contact about its pivot on said actuator as said actuator is moved from one of its limiting positions to the other.

6. In a switch of the class described, the combination of: a box; a cover hinged at one end to one end of said box in such a manner as to partially close the open side of said box when in its closed position; a pair of fixed contacts supported in and electrically insulated from said box and electrically insulated from each other; an actuator supported in said cover in such a manner as to be movable along a straight line within limits with relation to said cover; a bridging contact so shaped that in its bridging position it electrically connects one of said fixed contacts with the other of said xed contacts, said bridging contact being pivoted cn said actuator; and a cam member fixed with relation to said cover and so placed as to swing said bridging contact about its pivot on said actuator as said actuator is moved from one of its limiting positions to the other, said parts being so proportioned that the cover can be closed with said bridging contact in either of its extreme positions about its pivot with relation to said cover.

7. In a switch of the class described, the combination of: a box; a cover hinged at one end to one end ci said box in such a manner as to partially close the open side of said box when in its closed position; a pair of fixed contacts supported in and electrically insulated from said box and electrically insulated from each other; an actuator supported in said cover in such a manner as to be movable along a straight line within limits with relation to said cover; a U-shaped bridging Contact so shaped that in its bridging position it electrically connects one of said fixed contacts with the other of said xed contacts, said bridging contact being pivoted on said actuator; and a cam member fixed with relation to said cover and extending between the arms or" said U-shaped bridging contact, being so placed as to swing said bridging contact about its pivot on said actuator as said actuator is moved from one of its limiting positions to the other, said parts being so proportioned that the cover can be closed with said bridging contact in either of its extreme positions about its pivot with relation to said cover.

ALLAN I-l. WILSON.

REFERENCES CITED The following references are oi record in the file of this patent:

UNITED STATES PATENTS Name Date Jirka et al Feb. 7, 1933 Rowe Apr. 20, 1937 

